Excavator propulsion system and excavator

Abstract

The application relates to the technical field of excavators, and provides an excavator propulsion system and an excavator. The excavator propulsion system comprises a first side foot pedal valve group, a second side foot pedal valve group, a first side control valve group, a second side control valve group, a first walking unit and a second walking unit. The inlet end of the first side control valve group and the inlet end of the second side control valve group are connected with the outlet end of the first side foot pedal valve group, and / or the inlet end of the second side control valve group and the inlet end of the first side control valve group are connected with the outlet end of the second side foot pedal valve group. The first walking unit is connected with the outlet end of the first side control valve group, and the second walking unit is connected with the outlet end of the second side control valve group. Moreover, the first walking unit and the second walking unit are used for driving the corresponding side of the excavator to advance or retreat. The excavator propulsion system and the excavator provided by the application can realize single-foot-pedal-driven straight propulsion of the excavator, and are beneficial to flexible operation of an operator.

Description

Technical Field

[0001] This application relates to the field of excavator technology, and more particularly to an excavator propulsion system and an excavator. Background Technology

[0002] In some operating conditions of existing excavators, there is often a need for straight-line movement. For example, when using an excavator for weeding, it is often necessary to move forward and backward in a straight line for an extended period. Since current excavator propulsion methods typically involve controlling the forward and backward movement of the corresponding side's travel device with a single pedal, when the excavator needs to move straight, the operator must simultaneously depress both pedals with consistent force, which is very difficult for the operator. Furthermore, prolonged simultaneous and equal-force depressing of both pedals can easily lead to numbness in the operator's legs, resulting in uneven force application and potentially causing the excavator to veer off course.

[0003] Therefore, a new type of excavator propulsion system is needed to enable single-pedal drive for excavator straight-line movement, thereby reducing the difficulty of operation for operators and facilitating their flexible driving. Utility Model Content

[0004] This application provides an excavator propulsion system and an excavator to solve the problem in the prior art where the excavator cannot be driven straight by a single foot pedal, resulting in inconvenient operation.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] The first aspect of this application provides an excavator propulsion system, comprising: a first-side foot pedal valve group and a second-side foot pedal valve group; a first-side control valve group and a second-side control valve group; the inlet end of the first-side control valve group and the inlet end of the second-side control valve group are both connected to the outlet end of the first-side foot pedal valve group, and / or, the inlet end of the second-side control valve group and the inlet end of the first-side control valve group are both connected to the outlet end of the second-side foot pedal valve group; a first travel unit connected to the outlet end of the first-side control valve group; a second travel unit connected to the outlet end of the second-side control valve group; and the first travel unit and the second travel unit are used to drive the excavator forward or backward on corresponding sides.

[0007] As an optional implementation, the first side foot valve assembly includes a first foot valve and a second foot valve, and the second side foot valve assembly includes a third foot valve and a fourth foot valve; the first side control valve assembly includes a first control valve and a second control valve, and the second side control valve assembly includes a third control valve and a fourth control valve; wherein, the outlet end of the first foot valve is connected to the inlet end of the first control valve and the inlet end of the third control valve; the outlet end of the second foot valve is connected to the inlet end of the second control valve and the inlet end of the fourth control valve; the outlet end of the third foot valve is connected to the inlet end of the third control valve; and the outlet end of the fourth foot valve is connected to the inlet end of the fourth control valve.

[0008] As an optional implementation, it also includes a handle and a controller, the handle being electrically connected to the controller; and the handle having a first steering portion and a second steering portion; when the first steering portion is activated, the controller cuts off the first side control valve group; when the second steering portion is activated, the controller cuts off the second side control valve group.

[0009] As an optional implementation, it also includes an input device, which is electrically connected to the controller, or the input device is communicatively connected to the controller.

[0010] As an optional implementation, both the first traveling unit and the second traveling unit include a reversing valve and an actuator, with the actuator connected to the reversing valve; the reversing valve in the first traveling unit is connected to the outlet end of the first-side control valve group, and the reversing valve in the second traveling unit is connected to the outlet end of the second-side control valve group.

[0011] As an optional implementation, the directional valve of the first traveling unit has a first hydraulic control end and a second hydraulic control end; the directional valve of the second traveling unit has a third hydraulic control end and a fourth hydraulic control end; the first hydraulic control end is connected to the outlet end of the first control valve in the first side control valve group, the second hydraulic control end is connected to the outlet end of the second control valve in the first side control valve group, the third hydraulic control end is connected to the outlet end of the third control valve in the second side control valve group, and the fourth hydraulic control end is connected to the outlet end of the fourth control valve in the second side control valve group.

[0012] As an optional implementation, the directional valve has three operating positions; when the directional valve is in the first operating position, the oil passage between the directional valve and the actuator is cut off; when the directional valve is in the second operating position, the oil passage between the directional valve and the actuator is connected and flows in a first direction; when the directional valve is in the third operating position, the oil passage between the directional valve and the actuator is connected and flows in a second direction.

[0013] As an optional implementation, it also includes an oil pump assembly for supplying oil to the first side foot pedal valve assembly, the second side foot pedal valve assembly, the first travel unit, and the second travel unit.

[0014] As an optional implementation, the oil pump assembly includes: a first oil pump, the outlet of which is connected to the inlet of the first travel unit; a second oil pump, the outlet of which is connected to the inlet of the second travel unit; and a pilot oil pump, the outlet of which is connected to the inlet of both the first side foot pedal valve assembly and the second side foot pedal valve assembly.

[0015] A second aspect of this application provides an excavator including the excavator propulsion system described above.

[0016] The excavator propulsion system and excavator provided in this application include a first side foot pedal valve group, a second side foot pedal valve group, a first side control valve group, a second side control valve group, a first travel unit, and a second travel unit.

[0017] The inlet of the first control valve group and the inlet of the second control valve group are both connected to the outlet of the first foot valve group, and / or the inlet of the second control valve group and the inlet of the first control valve group are both connected to the outlet of the second foot valve group.

[0018] The first travel unit is connected to the outlet end of the first side control valve group, and the second travel unit is connected to the outlet end of the second side control valve group. Furthermore, the first and second travel units are used to drive the excavator forward or backward on the corresponding side.

[0019] With this configuration, when only one foot is used to trigger either the first or second side foot pedal valve group, both the first and second side control valve groups can be connected to the outlet end of the triggered foot pedal valve group. Therefore, the first and second side control valve groups can be used to control the synchronous movement of the corresponding first and second travel units, thereby controlling the excavator's straight-line propulsion. This not only reduces the operational difficulty and labor intensity for excavator operators but also facilitates flexible driving operations, ultimately improving work efficiency. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic diagram of the hydraulic principle of the excavator propulsion system provided in this application embodiment when the foot pedal valve group is not triggered;

[0022] Figure 2A schematic diagram of the hydraulic principle of the excavator propulsion system provided in the embodiments of this application, which triggers the first side foot pedal valve group in the first propulsion mode;

[0023] Figure 3 A schematic diagram of the hydraulic principle of an excavator propulsion system provided in this application embodiment triggering the first side foot pedal valve group in the second propulsion mode;

[0024] Figure 4 This is a schematic diagram of another hydraulic principle for triggering the first side foot pedal valve group in the second propulsion mode of the excavator propulsion system provided in the embodiments of this application.

[0025] Explanation of reference numerals in the attached figures:

[0026] 110 - First side foot valve assembly; 111 - First foot valve; 112 - Second foot valve;

[0027] 120 - Second foot pedal valve assembly; 121 - Third foot pedal valve; 122 - Fourth foot pedal valve;

[0028] 210 - First side control valve assembly; 211 - First control valve; 212 - Second control valve;

[0029] 220 - Second side control valve assembly; 221 - Third control valve; 222 - Fourth control valve;

[0030] 310 - First traveling unit; 320 - Second traveling unit; 330 - Directional control valve; 340 - Actuator;

[0031] 400-Controller;

[0032] 510 - Handle; 511 - First steering unit; 512 - Second steering unit;

[0033] 520 - Input device;

[0034] 600 - Oil pump assembly; 610 - First oil pump; 620 - Second oil pump; 630 - Pilot oil pump;

[0035] 700-Filter;

[0036] 810 - Fuel tank; 820 - Return fuel tank;

[0037] 900-engine;

[0038] 1-First port; 2-Second port; 3-Third port; 4-Fourth port; 5-Fifth port; 6-Sixth port; 7-Seventh port. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0040] As excavators are used in more and more different fields, their functions are becoming increasingly diversified. In addition to digging materials, existing excavators also need to clamp and transfer materials.

[0041] In some operating conditions of existing excavators, there is often a need for the excavator to move forward in a straight line. For example, when using an excavator for weeding, it is usually necessary for the excavator to move forward and backward in a straight line for an extended period of time.

[0042] Because existing excavator propulsion methods use a single pedal to control the travel mechanism on one side, when the excavator needs to move straight, the operator must simultaneously depress both pedals with consistent force, which is extremely difficult for the operator. Furthermore, prolonged simultaneous and equal-force depressing of both pedals can easily lead to numbness in the operator's legs and feet, resulting in uneven force application and potentially causing the excavator to veer off course.

[0043] For example, in forestry applications, excavators need to use a log clamp to hold a bundle of timber, operate the handles and clamp buttons with both hands, and transport the timber to a construction site 50 meters away. If the existing excavator operation method is used, both feet need to simultaneously pedal the left and right pedals for a long time, and the force applied by both feet must be equal, making speed difficult to control, causing fatigue, and making it easy to veer off course.

[0044] In order to overcome the defects in the prior art, this application provides an excavator propulsion system and an excavator. The excavator propulsion system includes a first side foot pedal valve group, a second side foot pedal valve group, a first side control valve group, a second side control valve group, a first travel unit, and a second travel unit.

[0045] The inlet of the first control valve group and the inlet of the second control valve group are both connected to the outlet of the first foot valve group, and / or the inlet of the second control valve group and the inlet of the first control valve group are both connected to the outlet of the second foot valve group.

[0046] The first travel unit is connected to the outlet end of the first side control valve group, and the second travel unit is connected to the outlet end of the second side control valve group. Furthermore, the first and second travel units are used to drive the excavator forward or backward on the corresponding side.

[0047] With this configuration, when only one foot is used to trigger the first or second foot pedal valve group, both the first and second control valve groups can be connected to the outlet end of the triggered foot pedal valve group. Thus, the first and second travel units can be controlled to move synchronously through the first and second control valve groups to achieve control of the excavator's straight-line propulsion.

[0048] This not only reduces the difficulty of operating the excavator and the intensity of labor for the operators, but also allows for more flexible driving operations, thereby improving work efficiency.

[0049] The contents of this application will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can have a clearer and more detailed understanding of the contents of this application.

[0050] Figure 1 This is a schematic diagram of the hydraulic principle of the excavator propulsion system provided in the embodiment of this application when the foot pedal valve group is not triggered.

[0051] Reference Figure 1 As shown in the figure, this application embodiment provides an excavator propulsion system, which includes: a first side foot pedal valve group 110, a second side foot pedal valve group 120, a first side control valve group 210, a second side control valve group 220, a first travel unit 310, and a second travel unit 320.

[0052] It should be noted that the first side foot pedal valve assembly 110 can correspond to the right pedal, and the second side foot pedal valve assembly 120 can correspond to the left pedal. Alternatively, the first side foot pedal valve assembly 110 can correspond to the left pedal, and the second side foot pedal valve assembly 120 can correspond to the right pedal; no specific limitation is made here.

[0053] The inlet end of the first side control valve group 210 and the inlet end of the second side control valve group 220 are both connected to the outlet end of the first side foot pedal valve group 110, and / or the inlet end of the second side control valve group 220 and the inlet end of the first side control valve group 210 are both connected to the outlet end of the second side foot pedal valve group 120.

[0054] The first travel unit 310 is connected to the outlet end of the first side control valve group 210, and the second travel unit 320 is connected to the outlet end of the second side control valve group 220. Furthermore, the first travel unit 310 and the second travel unit 320 are used to drive the excavator forward or backward on the corresponding side.

[0055] For example, refer to Figure 1As shown, the inlet end of the first side control valve group 210 and the inlet end of the second side control valve group 220 can both be connected to the outlet end of the first side foot pedal valve group 110. In this case, triggering the first side foot pedal valve group 110 alone can simultaneously connect the outlet end of the first side foot pedal valve group 110 to the inlet ends of the first side control valve group 210 and the second side control valve group 220, thereby simultaneously controlling the first walking unit 310 and the second walking unit 320 to achieve corresponding linear actions.

[0056] Similarly, when the inlet end of the second side control valve group 220 and the inlet end of the first side control valve group 210 are both connected to the outlet end of the second side foot pedal valve group 120, triggering the second side foot pedal valve group 120 alone can simultaneously connect the outlet end of the second side foot pedal valve group 120 to the inlet ends of the first side control valve group 210 and the second side control valve group 220, thereby simultaneously controlling the first walking unit 310 and the second walking unit 320 to achieve corresponding linear actions.

[0057] When the inlet end of the first side control valve group 210 and the second side control valve group 220 is connected to both the outlet end of the first side foot pedal valve group 110 and the outlet end of the second side foot pedal valve group 120, regardless of whether the first side foot pedal valve group 110 or the second side foot pedal valve group 120 is triggered individually, the outlet end of the triggered foot pedal valve group can be connected to the inlet end of the first side control valve group 210 and the second side control valve group 220, thereby simultaneously controlling the first walking unit 310 and the second walking unit 320 to achieve corresponding linear actions.

[0058] With the above settings, the excavator can be driven to move forward in a straight line simply by triggering a single foot pedal. This not only reduces the difficulty of operation and the labor intensity for excavator operators, but also facilitates flexible driving operations and improves work efficiency.

[0059] It is understandable that when the first side foot pedal valve group 110 corresponds to the right pedal and the second side foot pedal valve group 120 corresponds to the left pedal, the first travel unit 310 can be used to drive the excavator to travel on the right side, and the second travel unit 320 can be used to drive the excavator to travel on the left side. The reverse is also true, and will not be elaborated here.

[0060] For ease of description, the first side foot pedal valve group 110 is used to correspond to the right pedal and the second side foot pedal valve group 120 is used to describe this application.

[0061] Continue to refer to Figure 1As shown, the first side foot pedal valve group 110 may include a first foot pedal valve 111 and a second foot pedal valve 112, and the second side foot pedal valve group 120 includes a third foot pedal valve 121 and a fourth foot pedal valve 122. In the initial state, the first foot pedal valve 111, the second foot pedal valve 112, the third foot pedal valve 121, and the fourth foot pedal valve 122 are all in the closed state.

[0062] The first-side control valve group 210 includes a first control valve 211 and a second control valve 212, and the second-side control valve group 220 includes a third control valve 221 and a fourth control valve 222. In the initial state, the first control valve 211, the second control valve 212, the third control valve 221, and the fourth control valve 222 are all in the connected state.

[0063] In one embodiment, the outlet of the first foot valve 111 can be connected to the inlet of the first control valve 211 and the inlet of the third control valve 221. The outlet of the second foot valve 112 can be connected to the inlet of the second control valve 212 and the inlet of the fourth control valve 222. The outlet of the third foot valve 121 can be connected to the inlet of the third control valve 221. The outlet of the fourth foot valve 122 can be connected to the inlet of the fourth control valve 222.

[0064] In this way, by triggering the first foot valve 111 or the second foot valve 112, the simultaneous forward or backward movement of the two travel units on both sides of the excavator can be controlled individually and precisely, further improving the reliability of the excavator's movement. Furthermore, it can reduce the number of pipelines in the hydraulic system, thereby saving pipeline layout costs and internal space.

[0065] For example, the first foot pedal valve 111 can be a right front foot pedal valve, and the second foot pedal valve 112 can be a right rear foot pedal valve. Correspondingly, the first foot pedal valve 111 can be used to control the forward movement of the first travel unit 310 (the right-side travel unit of the excavator). The second foot pedal valve 112 can be used to control the backward movement of the first travel unit 310 (the right-side travel unit of the excavator).

[0066] The third foot valve 121 can be a left front foot valve, and the fourth foot valve 122 can be a left rear foot valve. Correspondingly, the third foot valve 121 can be used to control the forward movement of the second travel unit 320 (the left travel unit of the excavator). The fourth foot valve 122 can be used to control the reverse movement of the second travel unit 320 (the left travel unit of the excavator).

[0067] Understandably, the right foot is usually the operator's dominant foot when driving a vehicle. The first foot pedal valve 111 and the second foot pedal valve 112 correspond to the right front foot pedal valve and the right rear foot pedal valve, which is more in line with the operator's daily usage habits and can further improve the user's ease of operation.

[0068] In another implementation, the outlet of the first foot valve 111 can be connected to the inlet of the first control valve 211 and the inlet of the third control valve 221. The outlet of the second foot valve 112 can be connected to the inlet of the second control valve 212 and the inlet of the fourth control valve 222. The outlet of the third foot valve 121 can be connected to the inlet of the third control valve 221 and the inlet of the first control valve 211. The outlet of the fourth foot valve 122 can be connected to the inlet of the fourth control valve 222 and the inlet of the second control valve 212.

[0069] Understandably, in Figure 1 Based on this, an oil passage can be added between the outlet of the third foot valve 121 and the inlet of the third control valve 221 to connect the inlet of the first control valve 211 and the outlet of the third foot valve 121. Furthermore, an oil passage can be added between the outlet of the fourth foot valve 122 and the inlet of the fourth control valve 222 to connect the inlet of the second control valve 212 and the outlet of the fourth foot valve 122.

[0070] In this way, the excavator's straight-line movement can be controlled by triggering the corresponding foot valve in either pedal, resulting in better system redundancy.

[0071] Continue to refer to Figure 1 As shown, the excavator propulsion system may also include a handle 510 and a controller 400. The handle 510 is electrically connected to the controller 400. Thus, the handle 510 can transmit the user's operating intentions to the controller 400 via electrical signals.

[0072] Furthermore, the handle 510 has a first steering portion 511 and a second steering portion 512. When the first steering portion 511 is activated, the controller 400 shuts off the first-side control valve group 210. When the second steering portion 512 is activated, the controller 400 shuts off the second-side control valve group 220.

[0073] For example, taking the first side foot pedal valve group 110 corresponding to the right side pedal and being triggered as an example, when the first steering unit 511 is in an active state, the corresponding first side control valve group 210 can be shut off. Subsequently, the first travel unit 310 no longer drives the right side of the excavator to move.

[0074] Since the inlet of the second-side control valve group 220 is connected to the outlet of the first-side foot pedal valve group 110, the second-side control valve group 220 is still in a connected state, thus enabling the second travel unit 320 to drive the excavator to move to the left. Consequently, the excavator can turn right.

[0075] When the second steering unit 512 is activated, the corresponding second-side control valve group 220 can be shut off. Consequently, the second travel unit 320 no longer drives the excavator to move to the left. At this time, the first-side control valve group 210 remains connected, thus allowing the first travel unit 310 to control the excavator to move to the right. Consequently, the excavator can turn left.

[0076] Specifically, when the first foot pedal valve 111 (right front foot pedal valve) is triggered and the first steering unit 511 is activated, the controller 400 can send a signal to the control terminal of the first control valve 211 to shut off the first control valve 211, and the first travel unit 310 stops driving the excavator to the right. At this time, the third control valve 221 can still drive the second travel unit 320 forward, thereby enabling the excavator to turn right.

[0077] When the first foot pedal valve 111 (right front foot pedal valve) is triggered and the second steering unit 512 is activated, the controller 400 can send a signal to the control terminal of the third control valve 221 to shut off the third control valve 221, stopping the second travel unit 320 from driving the excavator to the left. At this time, the first control valve 211 can still drive the first travel unit 310 forward, thus enabling the excavator to turn left.

[0078] In this way, whether it is during the process of single-foot straight-forward propulsion or the start-up phase of the excavator, steering control towards any side can be achieved by activating the first steering part 511 or the second steering part 512 on the handle 510.

[0079] For example, when moving straight forward with one foot, if a right or left turn is needed, simply activate the first steering unit 511 or the second steering unit 512 to turn right or left. After the direction adjustment is complete, the activation of the first steering unit 511 or the second steering unit 512 can be deactivated, and straight forward movement can continue with one foot. The entire operation is flexible and convenient.

[0080] It is understood that in some other embodiments, the first steering unit 511 and the second steering unit 512 may also be disposed on other components that are electrically or communicatively connected to the controller 400, such as a display screen, control panel or remote control.

[0081] It should be noted that the first steering part 511 and the second steering part 512 may be different buttons on the handle 510, different joysticks on the handle 510, or different gears of the same joystick. No specific limitation is made here.

[0082] In some embodiments, the excavator propulsion system may further include an input device 520. The input device 520 may be electrically connected to the controller 400, or the input device 520 may be communicatively connected to the controller 400. It is understood that the input device 520 may be a display screen, a control panel, or a remote control.

[0083] For example, the input device 520 may be a display screen, and the controller 400 is electrically connected to both the input device 520 and the handle 510.

[0084] The controller 400 may have seven ports: port 1, port 2, port 3, port 4, port 5, port 6, and port 7.

[0085] Among them, the first port 1 and the second port 2 of the controller 400 are connected to the handle 510, the seventh port 7 is connected to the input device 520, and the sixth port 6, the fifth port 5, the fourth port 4 and the third port 3 are respectively connected to the control terminals of the first control valve 211, the second control valve 212, the third control valve 221 and the fourth control valve 222, thereby realizing the switching control of the corresponding control valves.

[0086] Furthermore, the input device 520 can be used to select and switch between the first propulsion mode and the second propulsion mode.

[0087] The first propulsion mode is the traditional excavator propulsion mode.

[0088] For example, stepping forward or backward with the right foot triggers the first foot pedal valve 111 or the second foot pedal valve 112, which in turn drives the right-side traveling unit of the excavator to move forward or backward.

[0089] Stepping forward or backward with the left foot triggers the third foot pedal valve 121 or the fourth foot pedal valve 122, which in turn drives the excavator's left-side traveling unit to move forward or backward.

[0090] When the left and right foot pedals move forward simultaneously, or the left and right foot pedals move backward simultaneously, the first foot pedal valve 111 and the third foot pedal valve 121 are triggered, or the second foot pedal valve 112 and the fourth foot pedal valve 122 are triggered, which simultaneously drives the left and right walking units of the excavator to move forward or backward, thereby realizing the straight-line propulsion of the excavator.

[0091] The second propulsion mode is the single-foot straight-line propulsion mode.

[0092] For example, stepping forward or backward with the right foot will trigger the first foot pedal valve 111 and the third foot pedal valve 121, or the second foot pedal valve 112 and the fourth foot pedal valve 122, which will simultaneously drive the excavator's left and right walking units to move forward or backward, thereby enabling the excavator to move straight forward.

[0093] Furthermore, during this process, if a left or right turn is required, simply activating the first steering unit 511 or the second steering unit 512 will enable turning left or right while advancing straight with one foot. Once the direction is adjusted, deactivating the first steering unit 511 or the second steering unit 512 will allow continued straight-line advancement with one foot.

[0094] In this way, the input device 520 can be used to select and switch between the first propulsion mode and the second propulsion mode, which is beneficial for operators to make flexible choices according to different operational needs.

[0095] In one implementation, both the first traveling unit 310 and the second traveling unit 320 may include a directional valve 330 and an actuator 340. The actuator 340 and the directional valve 330 can be connected via an oil circuit. The directional valve 330 can switch the flow direction of the hydraulic oil within the actuator 340. Specifically, the actuator 340 may include a hydraulic motor, which can drive the excavator track on the corresponding side.

[0096] Furthermore, the reversing valve 330 in the first travel unit 310 is connected to the outlet end of the first side control valve group 210, and the reversing valve 330 in the second travel unit 320 is connected to the outlet end of the second side control valve group 220.

[0097] By setting the reversing valve 330, the flow direction of hydraulic oil in the actuator 340 can be switched, thereby enabling the excavator to move forward or backward on one or both sides.

[0098] For example, the directional valve 330 of the first traveling unit 310 has a first hydraulic control terminal and a second hydraulic control terminal. The directional valve 330 of the second traveling unit 320 has a third hydraulic control terminal and a fourth hydraulic control terminal.

[0099] Specifically, the first hydraulic control terminal is connected to the outlet of the first control valve 211 in the first side control valve group 210. The second hydraulic control terminal is connected to the outlet of the second control valve 212 in the first side control valve group 210. The third hydraulic control terminal is connected to the outlet of the third control valve 221 in the second side control valve group 220. The fourth hydraulic control terminal is connected to the outlet of the fourth control valve 222 in the second side control valve group 220.

[0100] In this way, the hydraulic oil flowing out of the outlet end of the first control valve 211 can flow from the first hydraulic control end into the reversing valve 330 of the first travel unit 310, and then flow towards the actuator 340 in the first direction. The hydraulic oil flowing out of the outlet end of the second control valve 212 can flow from the second hydraulic control end into the reversing valve 330 of the first travel unit 310, and then flow towards the actuator 340 in the second direction.

[0101] Hydraulic oil flowing from the outlet of the third control valve 221 can flow from the third hydraulic control end into the reversing valve 330 of the second travel unit 320, and then flow towards the actuator 340 in the first direction. Hydraulic oil flowing from the outlet of the fourth control valve 222 can flow from the second hydraulic control end into the reversing valve 330 of the first travel unit 310, and then flow towards the actuator 340 in the second direction. The first direction is opposite to the second direction, so as to drive the left and right sides of the excavator to move forward or backward. For example, the first direction can be clockwise flow and the second direction can be counterclockwise flow.

[0102] In some embodiments, the directional control valve 330 has three operating positions. When the directional control valve 330 is in the first operating position, the oil passage between the directional control valve 330 and the actuator 340 is cut off. When the directional control valve 330 is in the second and third operating positions, the oil passage between the directional control valve 330 and the actuator 340 is connected.

[0103] For example, when the directional valve 330 is in the second operating position, the oil passage between the directional valve 330 and the actuator 340 is connected, and the oil flows in a first direction. When the directional valve 330 is in the third operating position, the oil passage between the directional valve 330 and the actuator 340 is connected, and the oil flows in a second direction.

[0104] Understandably, in the initial state, the directional valve 330 is in the first working position, at which time the oil circuit between the directional valve 330 and the actuator 340 is cut off. When hydraulic oil is injected into either hydraulically controlled end of the directional valve 330, the directional valve 330 can switch from the first working position to the second or third working position, thereby realizing the connection of the oil circuit.

[0105] For example, taking the first travel unit 310 as an example, when the excavator is in the second propulsion mode (single foot pedal straight propulsion mode) and the first foot pedal valve 111 is activated, hydraulic oil can flow from the outlet end of the first control valve 211 to the first hydraulic control end of the directional valve 330 in the first travel unit 310, causing the valve core of the directional valve 330 to move to the right, and the oil passage between the directional valve 330 and the actuator 340 flows in the first direction.

[0106] Simultaneously, hydraulic oil can flow from the outlet of the third control valve 221 to the third hydraulic control end of the directional valve 330 in the second travel unit 320, causing the valve core of the directional valve 330 to move to the left. The oil passage between the directional valve 330 and the actuator 340 flows in the first direction. This allows the excavator to be driven to travel to the left and right simultaneously, achieving straight-line forward movement. When other foot pedal valves are activated, their operation is similar to the above process and will not be described in detail here.

[0107] In this way, by driving the injection of hydraulic oil into different hydraulic control ends of the directional valve 330, the directional valve 330 can be switched, and the excavator can be driven to perform the corresponding action.

[0108] Continue to refer to Figure 1 As shown, the excavator propulsion system also includes an oil pump assembly 600, which can supply oil to the first side foot pedal valve assembly 110, the second side foot pedal valve assembly 120, the first travel unit 310, and the second travel unit 320. The oil pump assembly 600 is connected to the engine 900, and can convert the mechanical energy of the engine 900 into hydraulic energy to provide high-pressure oil to the excavator propulsion system.

[0109] The oil pump assembly 600 may include a first oil pump 610, a second oil pump 620, and a pilot oil pump 630. The outlet of the first oil pump 610 is connected to the inlet of the first travel unit 310. For example, the outlet of the first oil pump 610 is connected to the inlet of the directional valve 330 in the first travel unit 310. The outlet of the second oil pump 620 is connected to the inlet of the second travel unit 320. For example, the outlet of the second oil pump 620 is connected to the inlet of the directional valve 330 in the second travel unit 320. The outlet of the pilot oil pump 630 is connected to the inlets of both the first side foot pedal valve assembly 110 and the second side foot pedal valve assembly 120. The inlets of the first oil pump 610, the second oil pump 620, and the pilot oil pump 630 are connected to the oil tank 810.

[0110] In this way, the pilot hydraulic oil flowing out of the pilot oil pump 630 can be reversed by driving the reversing valve 330 in the first travel unit 310 and the second travel unit 320, so that the oil circuit between the reversing valve 330 and the actuator 340 is connected, and the first oil pump 610 and the second oil pump 620 can provide high pressure hydraulic oil to the first travel unit 310 and the second travel unit 320.

[0111] In one implementation, a filter 700 is provided between the outlet of the pilot oil pump 630 and the inlet of the first side foot valve assembly 110 and the second side foot valve assembly 120.

[0112] In this way, the filter 700 can intercept particulate impurities (such as metal shavings, colloids, etc.) in the oil, prevent valve core from sticking or wearing, ensure accurate transmission of control signals, maintain system pressure stability, and extend the service life of hydraulic oil.

[0113] As an optional implementation, at least one of the first side foot pedal valve assembly 110, the second side foot pedal valve assembly 120, the first travel unit 310, and the second travel unit 320 is provided with an oil return port. The oil return ports of the first side foot pedal valve assembly 110, the second side foot pedal valve assembly 120, the first travel unit 310, and the second travel unit 320 can be connected to the oil return tank 820.

[0114] For example, the first foot valve 111, the second foot valve 112, the third foot valve 121 and the fourth foot valve 122 can all be provided with oil return ports, so that the pilot oil circuit can be depressurized through the connection between the oil return ports and the oil return tank 820.

[0115] Both the first traveling unit 310 and the second traveling unit 320 can be provided with oil return ports. For example, the directional valves 330 of the first traveling unit 310 and the second traveling unit 320 can be provided with oil return ports, so as to release residual pressure when switching the oil circuit direction and avoid valve core jamming.

[0116] The actuators 340 of the first traveling unit 310 and the second traveling unit 320 may also be equipped with return ports, so that the low-pressure oil discharged from the hydraulic motor can be sent to the return oil tank 820 through the return ports to maintain the system pressure balance. When the hydraulic motor stops working, the return ports can also release residual pressure to avoid damage to the seals or rupture of the housing due to excessive back pressure.

[0117] The following combination Figures 2 to 4 The various operating conditions of the excavator propulsion system in the embodiments of this application will be further explained and described.

[0118] Figure 2 A schematic diagram of the hydraulic principle of the excavator propulsion system provided in the embodiments of this application, which triggers the first side foot pedal valve group in the first propulsion mode. Figure 3 This is a schematic diagram of the hydraulic principle of an excavator propulsion system provided in the embodiments of this application, which triggers the first side foot pedal valve group in the second propulsion mode. Figure 4 This is a schematic diagram of another hydraulic principle for triggering the first side foot pedal valve group in the second propulsion mode of the excavator propulsion system provided in the embodiments of this application.

[0119] When the excavator is in the first propulsion mode, that is, the traditional excavator propulsion mode, it can move forward on the right, backward on the right, forward on the left, backward on the left, and forward and backward in a straight line.

[0120] In the initial state, the first foot valve 111, the second foot valve 112, the third foot valve 121, and the fourth foot valve 122 are all closed. The first control valve 211, the second control valve 212, the third control valve 221, and the fourth control valve 222 are all connected. The directional valves 330 of the first travel unit 310 and the second travel unit 320 are both in the neutral position (first working position), cutting off the oil circuit between the directional valve 330 and the actuator 340.

[0121] (1) Advance to the right: Refer to Figure 2As shown, when the right foot moves forward to operate the right foot pedal, the first foot pedal valve 111 is triggered to switch directions. Pilot hydraulic oil sequentially passes through the outlet end of the first foot pedal valve 111, the inlet end of the first control valve 211, and the outlet end of the first control valve 211 to reach the first hydraulic control end on the left side of the directional valve 330 of the first travel unit 310, pushing the valve core to move to the right. At this time, the high-pressure hydraulic oil in the first oil pump 610 reaches the corresponding actuator 340 (right hydraulic motor) through the left valve position (second working position) of the directional valve 330, driving the excavator to travel forward to the right.

[0122] (2) Right-side reversing: When the right foot operates the right foot pedal backward, the second foot pedal valve 112 is triggered to reverse. The pilot hydraulic oil passes through the outlet end of the second foot pedal valve 112, the inlet end of the second control valve 212, and the outlet end of the second control valve 212 in sequence to the second hydraulic control end on the right side of the reversing valve 330 of the first travel unit 310, pushing the valve core to the left. At this time, the high-pressure hydraulic oil in the first oil pump 610 reaches the corresponding actuator 340 (right hydraulic motor) through the right valve position (third working position) of the reversing valve 330, driving the excavator to travel right and reverse.

[0123] (3) Leftward movement: When the left foot moves forward to operate the left foot pedal, the third foot pedal valve 121 is triggered to switch directions. The pilot hydraulic oil passes through the outlet end of the third foot pedal valve 121, the inlet end of the third control valve 221, and the outlet end of the third control valve 221 in sequence to the third hydraulic control end on the right side of the directional valve 330 of the second travel unit 320, pushing the valve core to move to the left. At this time, the high-pressure hydraulic oil in the second oil pump 620 passes through the right valve position (second working position) of the directional valve 330 to the corresponding actuator 340 (left hydraulic motor), driving the excavator to move forward to the left.

[0124] (4) Leftward Reverse Movement: When the left foot moves backward to operate the left foot pedal, the fourth foot pedal valve 122 is triggered to reverse. The pilot hydraulic oil passes sequentially through the outlet end of the fourth foot pedal valve 122, the inlet end of the fourth control valve 222, and the outlet end of the fourth control valve 222 to the fourth hydraulic control end on the left side of the reversing valve 330 of the second travel unit 320, pushing the valve core to the right. At this time, the high-pressure hydraulic oil in the second oil pump 620 passes through the left valve position (third working position) of the reversing valve 330 to the corresponding actuator 340 (left hydraulic motor), driving the excavator to travel leftward and reverse.

[0125] (5) Moving forward or backward in a straight line: Move the left and right feet forward at the same time or operate the left and right foot pedals one after the other. At this time, the first foot pedal valve 111 and the third foot pedal valve 121, or the second foot pedal valve 112 and the fourth foot pedal valve 122 are triggered to switch directions. The remaining working process can be referred to the above steps, which will not be repeated here.

[0126] The input device 520 (display screen) allows switching from the first push mode to the second push mode, or the second push mode can be activated directly.

[0127] When the excavator is in the second propulsion mode (single-foot pedal straight-forward propulsion mode), forward and backward movement can only be achieved by operating the right-hand pedal. To prevent accidental operation from affecting the excavator's normal movement, the input device 520 sends a signal to port 7 of the controller 400. The controller 400 receives the signal, performs logical judgment, and outputs a signal to the fourth control valve 222 through port 3, causing the fourth control valve 222 to switch. It can also output a signal to the third control valve 221 through port 4, causing the third control valve 221 to switch.

[0128] In this way, even if the operator accidentally operates the left pedal, it will not drive the left side to move, further enhancing safety. It should be noted that there is no signal output from the fifth port 5 and the sixth port 6, and the first control valve 211 and the second control valve 212 remain in their original positions.

[0129] In the second propulsion mode, the excavator can move forward in both directions, move backward in both directions, turn right, and turn left.

[0130] (1) Proceeding straight ahead on both sides: Refer to Figure 3 As shown, when the right foot moves forward to operate the right foot pedal, the first foot pedal valve 111 is switched, and the pilot hydraulic oil is divided into two paths after passing through the outlet end of the first foot pedal valve 111. One path goes through the first control valve 211 to the first hydraulic control end on the left side of the reversing valve 330 of the first travel unit 310, pushing the valve core to the right. The high-pressure hydraulic oil in the first oil pump 610 goes through the left valve position (second working position) of the reversing valve 330 to the corresponding actuator 340 (right hydraulic motor), driving the excavator to travel forward to the right.

[0131] Simultaneously, another path reaches the third hydraulic control end on the right side of the reversing valve 330 of the second travel unit 320 through the third control valve 221, pushing the valve core to move to the left. At this time, the high-pressure hydraulic oil in the second oil pump 620 reaches the corresponding actuator 340 (left hydraulic motor) through the right valve position (second working position) of the reversing valve 330, driving the excavator to travel forward to the left. Thus, the excavator can achieve the function of traveling straight forward on both sides.

[0132] (2) Left and right side straight and reverse: When the right foot operates the right foot pedal backward, the second foot pedal valve 112 is reversed. The pilot hydraulic oil is divided into two paths after passing through the outlet end of the second foot pedal valve 112. One path passes through the second control valve 212 to the second hydraulic control end on the right side of the reversing valve 330 of the first travel unit 310, pushing the valve core to the left. The high-pressure hydraulic oil in the first oil pump 610 passes through the right valve position (third working position) of the reversing valve 330 to the corresponding actuator 340 (right hydraulic motor), driving the excavator to travel right and reverse.

[0133] Simultaneously, another path passes through the fourth control valve 222 to the fourth hydraulic control end on the left side of the reversing valve 330 of the second travel unit 320, pushing the valve core to the right. At this time, the high-pressure hydraulic oil in the second oil pump 620 reaches the corresponding actuator 340 (left hydraulic motor) through the left valve position (third working position) of the reversing valve 330, driving the excavator to travel forward to the left. Thus, the excavator can achieve both left and right bilateral straight-ahead and reverse functions.

[0134] (3) Turn right while moving straight ahead (move forward on the left, stay on the right):

[0135] Reference Figure 4 As shown, if a right turn is required while moving straight forward, the first steering part 511 of the handle 510 can be activated (e.g., by pressing the right turn button on the handle 510), and a voltage signal will be output to the first port 1 of the controller 400.

[0136] After logic determination and calculation, the controller 400 outputs a voltage signal from port 6 to the control terminal of the first control valve 211. After being energized, the first control valve 211 reverses direction, that is, switches to the closed valve position.

[0137] At this time, the pilot hydraulic oil to the first hydraulic control end of the directional valve 330 of the first travel unit 310 is cut off, and the directional valve 330 returns to the neutral position. The high-pressure hydraulic oil of the first oil pump 610 is connected to the return oil tank 820. The corresponding actuator 340 (right-side hydraulic motor) stops rotating, that is, the excavator stops moving forward on the right. At this time, since the left side of the excavator continues to move forward while the right side stops moving, the excavator can realize the right turn function.

[0138] Understandably, the excavator can also start and turn right directly. By activating the first steering unit 511 (by pressing the right turn button on the handle 510), a voltage signal is output to the first port 1 of the controller 400. After logical judgment and calculation, the controller 400 outputs a voltage signal from the sixth port 6 to the first control valve 211. After being energized, the first control valve 211 switches to the closed position.

[0139] Operating the first foot valve 111 reverses its direction, allowing pilot hydraulic oil to flow through the first foot valve 111 and the third control valve 221 to the third hydraulic control terminal on the right side of the reversing valve 330 in the second travel unit 320, pushing the valve core to the left. At this time, the high-pressure oil in the second oil pump 620 reaches the corresponding actuator 340 (left hydraulic motor) through the right valve position of the reversing valve 330, driving the excavator to travel left and achieve a right turn.

[0140] (4) Turn left while proceeding straight ahead (proceeding to the right, remaining stationary on the left):

[0141] During forward straight travel, if a left turn is required, the second steering part 512 of the handle 510 can be activated (e.g., by pressing the left turn button on the handle 510), and a voltage signal is output to the second port 2 of the controller 400. After logical judgment and calculation, the controller 400 outputs a voltage signal from the fourth port 4 to the third control valve 221. Upon being energized, the third control valve 221 reverses direction and switches to the closed position. At this time, the pilot hydraulic oil to the third hydraulic control end of the reversing valve 330 of the second travel unit 320 is cut off, and the reversing valve 330 returns to the neutral position. The high-pressure hydraulic oil of the second oil pump 620 is connected to the return oil tank 820. The corresponding actuator 340 (left hydraulic motor) stops rotating, that is, the excavator stops moving forward to the left. At this time, since the right side of the excavator continues to move forward while the left side stops moving, the excavator can achieve the left turn function.

[0142] Similarly, an excavator can start and turn left directly.

[0143] By activating the second steering unit 512 (pressing the left turn button on the handle 510), a voltage signal is output to the second port 2 of the controller 400. After logical judgment and calculation, the controller 400 outputs a voltage signal from the fourth port 4 to the third control valve 221. After being energized, the third control valve 221 switches to the closed position. That is, the pilot oil from the first foot valve 111, through the third control valve 221, to the right side of the reversing valve 330 of the second travel unit 320 is cut off. The corresponding actuator 340 (left hydraulic motor) does not work, and the left side of the excavator does not move.

[0144] Operating the first foot valve 111 reverses its direction, allowing pilot hydraulic oil to pass through the first foot valve 111 and the first control valve 211 to reach the first hydraulic control end on the left side of the reversing valve 330 of the first travel unit 310, pushing the valve core to the right. At this time, the high-pressure oil in the first oil pump 610 passes through the left valve position of the reversing valve 330 to reach the corresponding actuator 340 (the right hydraulic motor), driving the excavator to travel to the right and achieve a left turn.

[0145] It is understood that in some other embodiments, a rocker switch or push-button switch can be used instead of a display screen to switch between the first and second propulsion modes. The reversing valve 330 can be replaced by a two-position or higher reversing solenoid valve, or by a proportional solenoid valve.

[0146] It should be noted that the terms left, right, up, and down mentioned in the embodiments of this application refer only to the positions in the schematic diagram and are unrelated to the actual physical positions. Furthermore, in the various operations described above in the embodiments of this application, the excavator's movement speed can be controlled by adjusting the opening degree of any foot pedal valve.

[0147] This application also provides an excavator that includes the excavator propulsion system described above and has the same technical effects as the excavator propulsion system described above, which will not be described in detail here.

[0148] The excavator propulsion system and excavator provided in this application have the following beneficial effects:

[0149] 1) Two propulsion modes can be selected in the input device 520 (display screen) to adapt to different working conditions, making operation simple and reducing operator fatigue during long-term straight-line walking.

[0150] 2) In the second propulsion mode, when the right foot moves forward or backward to operate the right foot pedal, the actuators 340 of the first walking unit 310 and the second walking unit 320 will simultaneously push the left and right walking devices forward and backward, realizing single-foot pedal straight-line propulsion. The amount of pedaling force can control the walking speed and prevent deviation.

[0151] During this process, if a situation requires turning left or right, simply activate the first steering part 511 or the second steering part 512 on the handle 510 to turn right or left. After the direction is adjusted, deactivate the handle and continue walking in a straight line with one foot. The operation is flexible and convenient, which helps to improve work efficiency.

[0152] It should be noted that the embodiments referred to in the specification, such as "one embodiment," "embodiment," "exemplary embodiment," and "some embodiments," may include specific features, structures, or characteristics, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0153] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "one" can be understood to convey either singular or plural usage.

[0154] It should be readily understood that the terms “on,” “above,” and “on top of” in this application should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on something” but also “on something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0155] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90° or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An excavator propulsion system, characterized in that, include: First side foot pedal valve assembly and second side foot pedal valve assembly; A first-side control valve group and a second-side control valve group; the inlet end of the first-side control valve group and the inlet end of the second-side control valve group are both connected to the outlet end of the first-side foot pedal valve group, and / or, the inlet end of the second-side control valve group and the inlet end of the first-side control valve group are both connected to the outlet end of the second-side foot pedal valve group. The first walking unit is connected to the outlet end of the first side control valve group; The second traveling unit is connected to the outlet end of the second side control valve group; Furthermore, the first traveling unit and the second traveling unit are used to drive the excavator forward or backward on the corresponding side.

2. The excavator propulsion system according to claim 1, characterized in that, The first side foot valve group includes a first foot valve and a second foot valve, and the second side foot valve group includes a third foot valve and a fourth foot valve; the first side control valve group includes a first control valve and a second control valve, and the second side control valve group includes a third control valve and a fourth control valve. The outlet of the first foot valve is connected to the inlet of the first control valve and the inlet of the third control valve; the outlet of the second foot valve is connected to the inlet of the second control valve and the inlet of the fourth control valve; the outlet of the third foot valve is connected to the inlet of the third control valve; and the outlet of the fourth foot valve is connected to the inlet of the fourth control valve.

3. The excavator propulsion system according to claim 1, characterized in that, It also includes a handle and a controller, the handle being electrically connected to the controller; and the handle having a first steering portion and a second steering portion; When the first steering unit is activated, the controller shuts off the first side control valve group; when the second steering unit is activated, the controller shuts off the second side control valve group.

4. The excavator propulsion system according to claim 3, characterized in that, It also includes an input device, which is electrically connected to the controller, or the input device is communicatively connected to the controller.

5. The excavator propulsion system according to any one of claims 1-4, characterized in that, Both the first traveling unit and the second traveling unit include a reversing valve and an actuator, wherein the actuator is connected to the reversing valve; The reversing valve in the first traveling unit is connected to the outlet end of the first side control valve group, and the reversing valve in the second traveling unit is connected to the outlet end of the second side control valve group.

6. The excavator propulsion system according to claim 5, characterized in that, The reversing valve of the first traveling unit has a first hydraulic control terminal and a second hydraulic control terminal; the reversing valve of the second traveling unit has a third hydraulic control terminal and a fourth hydraulic control terminal. The first hydraulic control terminal is connected to the outlet end of the first control valve in the first side control valve group, the second hydraulic control terminal is connected to the outlet end of the second control valve in the first side control valve group, the third hydraulic control terminal is connected to the outlet end of the third control valve in the second side control valve group, and the fourth hydraulic control terminal is connected to the outlet end of the fourth control valve in the second side control valve group.

7. The excavator propulsion system according to claim 5, characterized in that, The reversing valve has three operating positions; When the directional valve is in the first working position, the oil circuit between the directional valve and the actuator is cut off; When the directional valve is in the second working position, the oil passage between the directional valve and the actuator is connected and flows in the first direction; When the directional valve is in the third working position, the oil passage between the directional valve and the actuator is connected and flows in the second direction.

8. The excavator propulsion system according to any one of claims 1-4, characterized in that, It also includes an oil pump assembly, which is used to supply oil to the first side foot pedal valve assembly, the second side foot pedal valve assembly, the first walking unit, and the second walking unit.

9. The excavator propulsion system according to claim 8, characterized in that, The oil pump assembly includes: The first oil pump, the outlet of the first oil pump is connected to the inlet of the first walking unit; The second oil pump has its outlet connected to the inlet of the second traveling unit. A pilot oil pump, the outlet of which is connected to the inlet of both the first side foot valve assembly and the second side foot valve assembly.

10. An excavator, characterized in that, Includes the excavator propulsion system as described in any one of claims 1-9.

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